Process of making stannous chlorid.



PATENTED JAN. 23, 1906.

- 0- E. AGKER.

NG STANNOUS CHLORID a. 1903. RENEWED JUNE14,1905.

PROCESS OF MAKI APPLICATION FILED JUNE UNITED STATES PATENT OFFICE.

CHARLES E. ACKER, OE NIAGARA FALLS, NEW YORK, ASSIGNOR T0 AGKER PRoO ss COMPANY, A CORPORATION OF NEW JERSEY.

PROCESS OF MAKING STANNOUS CHLORID.

Specification of Letters Iatent.

Patented J an. 23, 1906.

Application filed June 8, 1903. Renewed June 14, 1905. Serial No. 265,238-

To all whom it may concern.-

Be it known that 1', CHARLES E. AOKER, a citizen of the United States, residing at Niagara Falls, in the county of Niagara and State of NewYork, have invented certain new and useful Improvements in Methods of Making Stannous Chlorid, of which the following is a specification.

solution containing stannous c orid, subjecting the solution so produced to the action of free chlorin or a gaseous mixture containing free chlorin to convert a part or all of the tin contained in the solution into stannic chlorid, bringing said stannic chlorid into contact with further quantities oftin, and again converting it to stannic culorid, the operation being continued until the desired concentration is reached. As fully explained in said application, the concentration of stannicchlorid solutions as heretofore produced has been limited in practice by several factors. Thus it has been customary to prepare solutions of stannic chlorid by reactmg upon metallic tin with hydrochloric acid in solution, thereby forming stannous chlorid, and subsequently converting said stannous chlorid to stannic chlorid b .addition of potassium chlorate to the acid solution. This rocess is relatively expensive, since the ch Orin is derived from comparatively costly compounds hydrochloric acid and potassium chlorate-and is furthermore subject to the disadvantages that the solutions produced cannot in practice exceed a density of to 51 Baum and are contaminated by the presence of considerable quantities of otassium chloridderived from the reductlon of the chlorate. Furthermore, it is impractical to concentrate such solutions by reason of the loss of stannic chlorid by volatilization and the tendency of the solutions to become basic. Solutions of a density of Baum have been prepared by first producinga solution of stannous chlorid, concentrating the same to saturation, and subsequentlyconverting it by means of otassium chlorate to stannic chlorid; but t is process is an expensive one and the solutions Obtained are limited in con; centrationand are contaminated by potassium chlorid.

According to my method as above outlined able to produce solutions'of stannic chlorid having a specific ravity varying between 1.800 and 1.960. I have now'discovered that these hi hly concentrated and pure solutions of stamnc chlorid afford an extremely simple and economical source from which the di chlorid of tin, (SnCl commercially known as tin-crystals, may be pre ared in a state of substantial purity and wit out necessity for evaporating the solution at any stage of the process. I have discovered that if stannicchlorid solutions of a concentration equal to or exceeding 1.800 specific ravity be converted by contactwith meta lic tin to stannous chlorid solutions of a corresponding concentration the stannous chlorid will separate from said solutions in the form of crysconversion of the stannic chlorid in solution to stannous chlorid takes place at a tempera- .60 centigrade-a large'yield of the crystals will be obtained when the solution is permitted to cool. k H

I prefer to conduct the operation substansuitably-divided condition, is brought into contact with a liquid containing chlorin, whereby a solution of stannous chlorid is the presence of the metal and is brought into contact, preferably in a suitable reactiontower,with free chlorin or a gaseous mixture containing free chlorin. Thevstannous chlointo stannic chlorid, which is returned into contact with themetallic tin and permitted to remain in contact therewith until sufh v cient tinhas been dissolved to reduce the salt in whole or in part from the tetravalent to the divalent condition; It will be clear that the concentration of the stannous chlorid has been increased in dproportion to the quantity of metal dissolve and that by a series of repetitions of the process the concen tration may be brought to the point desired.

I prefer to carry out the process at a temtals' of a'high degree of purity and that if the tially as follows: Metallic tin, preferably in a formed. Said solution is then removed from.

rid is thereby converted wholly or in part and hereinafter more fully "described I am I ture above-the normalsay at about 50 to added thereto.

i at which stannic cliloridis volatili zed.

The highly-concentrated and Warm stannous-chlorid solutions produced as above doscribed are permitted. to remain in contact With metallic tin until substantially reducedto the divalent state and are then drawn oil and permitted to cool, whereupon the ston nous chlorid separates from solution in the form of crystals of substantisl purity.

For the conversion of the tin from itsdivalent to its tetravelent conditionit is neither necessary nor advisable to use pure chlorin gas; but the chlorin may be admixed with a large proportion of air or oxygen. Furthermore, I have discovered that the reaction is facilitated by the injection of steam into the chlorin, With the consequent formation of hydrochloric acid, or by the use of chlorin containing a certain proportion of hydro cliloric sold.

l have employed gaseous mixture containing ninety-five to ninetv-six per cen.t. oi? air, four to five per cent: clilorin, and. a small percentage of hydrochloric acid: It will be understood that the rese tion evolves a considerable amount of heat and that the tem perature, ii uncontrolled, Would rise rapidly to a point at which hydrochloric acid and stannic chlorid would be volatilized and the solution injuriously aiifected. The use dilute chlorin es described possesses the od vantage that portion of this heat is absorbed in raising the teninei roture of the large volume of as so provided and that therefore it is possi is to utilize larger absolute quantistannic chlorid upon. metallic tin and serves else to prevent the ii in tien oi oxychlorids of tin, the presenceoi i. hich is in general Lindesirable.

It Will he understood that the dilution of the. chlorin need not'be so es above indicated by Way of example and that propoe tionate effects are secured by the use of smaller roportions oi the diluent.

lit wil be obvious that the director: of the original liquid, vv'hich under the'conditions oi" my process is to become a solution. of stannous chlorid of high concentration, maybe con siderably varied. Tlhus voter may be our ployed or any desired proportion of stennic chlorid; stannous chlorid, hydrochloricscid, or stannous or stonnic oxychlorid may be In any case the result of the treatment by chlorin is to form it solvent for tin, and the result of the repeated utilization and regeneration of this solvent and its final stones conversion to the divalent state is to form so lutions of stannous chlorid of a concentration heretofore unattainable in a commercial Way, said solutions yielding crystals of stannous chlorid, as above described.

Suitable apparatus for carrying out my process is shown in the accompanying drewin'gs, wherein- Figure 1 shows in vertical section one form of apparatus which maybe used. Fig. 2 is a.

similar view showing a Modified form thereof, and Fig 3 is a sinnler View of a further modification.

Referring to Fig; l, 1' represents a vat or tank, which insy conveniently be of glazed earthen-were, 2 is a. storage-reservoir, and 3 a reactiontower, shown as of, the ltohrinann type, but which may-be of any desired cheracterr Means consisting of a conduit 4 and an aii'=-i11jection pipe 5 lending into the-lower portion thereof, are rovided for continuouisly or intermittent y conveying the so lution in tank I to the storage-reservoir 2. From said reservoir the liquid is permitted to llOW downwardly through tower 3and to return thence by conduit 6 to the vat l. The vat i containsla mlass of metallic tin 12, pref erably in s suitahly divided condition, end to maintain body of clear liquid in tlieregion of the inlet to the conduit 4 said conduit is surrounded by s'protective casing 7, which cnveniently provided with apertures 8 at the lower end for the edrnissionof the liquid.

' renresents e coclci 'or Withdrawing the solutionirom the FfiitCijlOlbtOWG-R which the'liquid after being subjected to the ection oi chlorin in the reaction-tower 3 is mitted to flow into one of a series of pressure tsnlcs 1', a number oi such tanks being pro vided end filled and discharged inv succession, as will be readily understood. Ssid tanlrs I contoin metallic tin l2, and after the solvent has been permitted to remain in contact there with for s sullicient time the tanlr is closed cirqoressure applied shove the surface oi the liquid by moons of a pipe 5, liquid being thereby forced to the super reservoir 2, from which it returns through the tower 3 ab e described. llt will be obvious that any suite menus for securing the circulation of the liquid may substituted for those described. 1 E l-hove shown a lruther modifies ti on Wl .erein intermediate tsnlt, towel; or 1G is provided to contain the metallic tin and permit the reaction therewith of the sol vent liquid from the tower. ln sold tank ill 1 hove shovvi'i s1 distributing-piste ii for inilioiving solution and a discharge-pipe i3 for the delivery of the same to the pressure tanlr or other elevating device l. ll 15 rep resentthe inlet and. outlet, respectively, for the gas, which serves to convert the tin from. its divalent to its tetrevalent condition. it is a pipe for the injection of steam into the 2 shovvs s modified form of device in chlorin in order to form therewith hydrochloric acid. 17 is a cock for withdrawing the solution from the pressure-tank.

To obtain the solution-containing tin in the divalentcondition, it may be withdrawn from the system at any point following the treatment with metallic tinsay from the vessels 1 1or itmay be'withdrawn after the treatment with chlorin and subjected in any suitable vessel to the action of metallic tin. Any stannic chlorid contained in the solution drawn from vessels 1 1 may of course be reduced by metallic tin, as hereinbefore described.

The apparatus herein shown is claimed in my copending application, Serial No: 160,566, filed June 8, 1903.

I claim 1. The method of making stannous chlorid which consists in bringing metallic tin into contact with a solvent containing chlorin, thereby producing a solution containing stannouschlorid, subjecting said solution to the action of a fluid containing free chlorin to form stannic-chlorid, and bringing said solution of stannic chlorid into contact with metallic tin to again form stannous chlorid, substantially as described.

2. The method of making stannous chlorid which consists in bringing metallic tin into contact'with a solvent containing chlorin, thereby producing a solution containing stannous chlorid, subjecting said solution to the action of a fluid containing free chlorin to form stannic chlorid, bringing said solution of stannic chlorid into contactwith metallic tin to again form stannous chlorid, and repeating the operation until the desired concentration is reached, substantially as de- 4 scribed.

3. The method of making stannous chlorid which consists in bringing metallic tin into contact with a solvent containing chlorin,

thereby producing a solution containing stannous c lorid, subjecting said solution to the action of free chlorin to form stannic chlorid, bringing said solution of stannic chlorid into contact with metallic tin to again form stannous chlorid, repeating the operation until the concentration of the stannic-chlorid solution exceeds 1.800, reducing said solution to stannous chlorid by contact with. tin, andpermitting said .stannous chlorid solution to crystallize, substantiall as described.

' 4. The method of ma 'ng stannous chlorid which consists in bringingmetallic tin into contact with a solvent containing chlorin at a temperature above normal, thereby producing a solution containing stannous chlorid, subjecting said solution to the action of a fluid containing free chlorin to form stannic chlorid, bringing said solution of stannic chlorid into contact. with metallic tin to again form stannous chlorid, repeating the operation until the concentration of the stannic-chlorid solution exceeds 1.800, reducing said solution to stannous chloridby contact with tin, and permitting said stannouschlo rid solution to cool, whereby crystals of stannous chlorid are obtained, substantially as described.

5. The method of making stannouschlorid which consists in bringing metallic tin into contact with a solvent containing chlorin, thereby producing a solution containing stannous chlorid, subjecting said solution to the action of a gaseous mixture containing free chlorin and hydrochloric acid to form stannic chlorid, and bringing said solution of stannic chlorid into contact with metallic tin to again form stannous chlorid, substantially as described.

6. The method of making stannous chlorid which consists in bringing metallic tin into contact with a solvent containing chlorin, thereby producing a solution containing stannous chlo'rid, subjecting said solution to the action of a gaseous mixture containing free chlorin, hydrochloric acid, and atmospheric air to form stannic chlorid, and bringing said solution of stannic chlorid into contact with metallic tin to again form stannous chlorid, substantially as described.

7. The herein-described method of producing' solutions containing stannous. chlorid, which consists in subjecting solutions containing tin to the successive action of a fluid containing free chlorin and metallic tin, substantially as described.

.8. The method of making stannous chlorid, which consists in subjecting solutions containing stannous chlorid to the action of a fluid containing free chlorin to form stannic chlorid, and bringing said stannic chlorid into contact with metallic tin, thereby producing a solution containing an increased amount of stannous chlorid, substantially as described. In testimony whereof I aflix my signature in presence of two witnesses.

CHARLES E. ACKER. Witnesses:

J. H. SOHERMERHORN, D. L. MAG-KAY. 

